Comparison of Organic Farming Systems Using Off-Farm Nitrogen with - without Animals

2004 Annual Report for LNE02-158

Project Type: Research and Education
Funds awarded in 2002: $149,968.00
Projected End Date: 12/31/2006
Matching Non-Federal Funds: $200,626.00
Region: Northeast
State: West Virginia
Project Leader:
Sven Verlinden
West Virginia University

Comparison of Organic Farming Systems Using Off-Farm Nitrogen with - without Animals


The objectives of this project are to evaluate the sustainability of organic farming systems that rely on biologically-fixed nitrogen versus those using off-farm nitrogen to maintain cropland, and to compare the production, soil quality, and environmental impacts of crops-only organic farming systems with systems integrating crops and livestock. The project continues one begun in 1999 when the West Virginia University Horticulture Farm underwent the transition to organic practices. Replicated field trials in vegetable (market garden) and field crops using a randomized factorial design are being continued through 2005. Plots receiving compost are amended with compost to supply 150 pounds nitrogen per acre each year to enhance soil fertility. A four-year crop rotation is being maintained in both market garden and field crop farming systems. In addition, in the field crop system, livestock production (sheep and poultry) and pasture are being integrated into half of the field crop systems. Pest management practices are being evaluated in replicated field plots and in on-farm trials with five grower-cooperators. Results are being communicated to growers, extension staff, and the public through field days, internet web pages, and other media outlets.

Objectives/Performance Targets

The overall objective of the project is to compare organic farming systems using biologically-derived nitrogen (legumes) with systems using supplemental nitrogen from off-farm composted manure. Soil quality, pest impacts, yields and economic performance are being measured and results are being communicated to growers.

Specific performance targets include:

1. Ten growers identified from our grower advisory committee, attendees at Farm Field Days, or commodity organizations, will base, at least in part, their compost use rates on soil quality and economic performance criteria developed from this phase of the project.

2. The proportion of growers that are transitioning from conventional to organic production that have incorporated research and cost-benefit results in their decision-making in designing a transition system for their operation will increase to 50 %.

3. Nine undergraduate students will be trained in organic farming practices through internships. Farm-related experience will be provided to additional undergraduate and graduate students through work experience, research opportunities, field days, and classroom and non-classroom activities.

4. Five growers per year, identified at field days and through direct contacts, will participate in on-farm evaluations/demonstrations of selected practices in the following year. These selected practices will include: use of barriers (row cover, particle film sprays, etc.) for pest management; rotation practices, diversification through integration of livestock into the farming system, and weed management using mulches.

5. Twelve producers will incorporate practices for management of internal parasites in sheep using either rotational grazing and/or alternating sheep and poultry on pastures.


Small plot trials continued evaluation of acetic acid as a weed management practice in potato. Yields in acetic acid plots were lower than in plots where weeds were managed by cultivation/hoeing.

Compost application rates were evaluated for optimum tomato yield and brassica cover crop response, with yields increasing as compost application rates increased from 0-20 tons per acre. Moderate compost application rates (2.5 and 5 tons per acre) increased early blight disease in tomato, compared to control plots, but very high compost rates (10 and 20 tons per acre) had disease levels comparable to controls. These trials expand the cropping evaluations from previous work with beans, millet, buckwheat and cut flowers.

In the farming systems trials, compost application rates were modified as high rates begin to saturate nutrient holding capacity of soils. Compost application is being restricted to crops that show maximum yield response (potato and wheat). Yields were usually higher with compost than without. A “decision tree” is under development to provide compost rate recommendations to growers.

Four undergraduate student interns were enrolled for the 2004 field season and worked in weed management, soil monitoring, horticultural production and crop/livestock systems integration. The 2004 Field Day was held August 5 and featured demonstrations, research tours, and hands-on workshops. Approximately 180 people attended.

Growers participating in on-farm evaluations of organic management practices evaluated use of floating row covers, and parasitic wasps for management of Mexican bean beetle. Six plots were established on farms throughout Monongalia and Preston County, West Virginia, with no plots closer than 1 km to its nearest neighbor. Growers had either floating row covers and the parasitic wasp, Pediobius faveolatus, or uncovered bean rows without the wasp. Row covers delayed production slightly but increased bean yields and suppressed bean beetle larval populations significantly over the season. Wasp application more than doubled bean yields. Bean beetle larval populations did not differ at the start of the season, but were significantly reduced in wasp plots in the second half of the growing season. All plots without wasps were almost completely defoliated by the end of the season, whereas all wasp release plots continued yielding until first frost.

Rotational grazing of sheep continues to maintain sheep with low intestinal parasite burdens, however, favorable environmental conditions and shortened rotations resulted in higher parasite burdens than in previous years. Poultry production integration with the existing sheep/crops production system continued in summer 2004, and “weeder geese” were evaluated in the market garden system. Pastured poultry without supplemental methionine in the ration achieved growth comparable to poultry with supplemental methionine in the ration. Weeder geese were successful in reducing weed competition in some crops, but crop damage from geese trampling occurred in other crops.

Impacts and Contributions/Outcomes

Growers continue to conduct on-farm evaluations of organic practices under study at the WVU Organic Research Farm. Grower participation at field days and in on-farm application of management practices has increased and student participation in the project is resulting in an increasing pool of trained practitioners. Scientific papers reporting results from the project were presented at meetings of the Weed Science Society of America, the American Phytopathological Society, and the Agronomy Society of America (Northeast Branch). Fact sheets have been prepared (see attached), with assistance and support from the West Virginia University Cooperative Extension program. Three manuscripts reporting research at the Farm have been submitted to scientific journals.